Cobalt Nocturne is a style LoRA inspired by vintage Cyanotype photography. Deep Prussian blues, indigos and subtle washes create a nice effect on illustrations, botanicals, and more. You can guide the style to a more vintage feel by adding things like "vintage border, vintage effects" in your positive. Additions such as "natural paper texture, Prussian blue" seem to also create some neat outputs.

Illustrious:
Trigger word : cobalt_nocturne
CFG - 5.5
Steps - 30
Sampler: Euler Ancestral / Beta 57 or Normal/Simple (play around and see which one you like best)

Anima:
Trigger word: cobaltnocturne
(tested with turbo LoRA)
CFG - 1
Steps - 12
Sampler: Euler / Simple

Krea2:
Trigger word: cobaltnocturne
(tested with turbo version)
CFG - 1
Steps - 8
Sampler: Euler / Simple (or whichever your checkpoint suggests)